Studies on the redox chemistry and electron transport properties of metalloporphyrins and metalloporphyrin containing enzymes such as catalase, peroxidase, cytochrome c, cytochrome P-450, and photosynthetic pigments proposed. BIBLIOGRAPHIC REFERENCES: DiNello, R.K., Rousseau, K. and Dolphin, D. A model for the Halogenating Agent of Chloroperoxidase, Annals New York Acad. Sci., 1975, 244, 94. DiNello, R.K. and Dolphin, D. Analytical Chromatography of Hemins on Silica Gel, Anal. Biochem, 1975, 64, 449.